Evaluating the discriminatory power of EQ-5D, HUI2 and HUI3 in a US general population survey using Shannon's indices

Health-Related Quality of Life in Romanian Patients with Dystonia: An Exploratory Study

Background/Objectives: Dystonia is a neurological movement disorder characterized by involuntary muscle contractions that lead to abnormal movements and postures; it has a major impact on patients' health-related quality of life (HRQoL). The aim of this study was to examine the HRQoL of Romanian patients with dystonia using the EQ-5D-5L instrument. Methods: Responses to the EQ-5D-5L and the visual analogue scale (VAS) were collected alongside demographic and clinical characteristics. Health profiles were analyzed via the metrics of the EQ-5D-5L, severity levels, and age groups. Using Shannon's indexes, we calculated informativity both for patients' health profile as a whole and each individual dimension. Level sum scores (LSS) of the EQ-5D-5L were calculated and compared with scores from the EQ-5D-5L index and VAS. The HRQoL measures were analyzed through demographic and clinical characteristics. Descriptive statistics, Spearman correlation, and non-parametric tests (Mann-Whitney U or Kruskall-Wallis H) were used. The level of agreement between HRQoL measures was assessed using their intraclass correlation coefficient (ICC) and Bland-Altman plots. Results: A sample of 90 patients was used, around 75.6% of whom were female patients, and the mean age at the beginning of the survey was 58.7 years. The proportion of patients reporting "no problems" in all five dimensions was 10%. The highest frequency reported was "no problems" in self-care (66%), followed by "no problems" in mobility (41%). Shannon index and Shannon evenness index values showed higher informativity for pain/discomfort (2.07 and 0.89, respectively) and minimal informativity for self-care (1.59 and 0.68, respectively). The mean EQ-5D-5L index, LSS, and VAS scores were 0.74 (SD = 0.26), 0.70 (SD = 0.24), and 0.61 (SD = 0.21), respectively. The Spearman correlations between HRQoL measures were higher than 0.60. The agreement between the EQ-5D-5L index and LSS values was excellent (ICC = 0.970, 95% CI = 0.934-0.984); the agreement was poor-to-good between the EQ-5D-5L index and VAS scores (ICC = 683, 95% CI = 0.388-0.820), and moderate-to-good between the LSS and VAS scores (ICC = 0.789, 95% CI = 0.593-0.862). Conclusions: Our results support the utilization of the EQ-5D-5L instrument in assessing the HRQoL of dystonia patients, and empirical results suggest that the EQ-5D-5L index and LSS measure may be used interchangeably. The findings from this study highlight that HRQoL is complex in patients with dystonia, particularly across different age groups.

Developing and testing culturally relevant bolt-on items for EQ-5D-5L in Chinese populations: a mixed-methods study protocol

INTRODUCTION

EQ-5D is one of the most frequently used health-related quality of life (HRQoL) measures but has been found to be insensitive in detecting differences in health status in some general populations and disease groups. For example, the appropriateness of applying EQ-5D in the Chinese cultural setting has been widely discussed. Adding additional HRQoL dimensions (bolt-on items) can be a solution to both retain the original descriptive system of EQ-5D, while enhancing its sensitivity to the local context. To date, no studies have proposed culturally relevant bolt-ons for China or examined the psychometric properties of such bolt-on items. This protocol documents the identification, development, selection and psychometric testing of culturally relevant bolt-on items for EQ-5D-5L in China.

METHODS AND ANALYSIS

We will identify and develop candidate bolt-on items that are most relevant in the Chinese culture, through former literature reviews on health concepts important for the Chinese population, conducting expert consultations and qualitative interviews. We will quantitatively test the acceptability and measurement properties (including distributional characteristics and construct validity) of the candidate items in both general and disease populations in a cross-sectional setting. The patient group will be followed up to collect two-time-point data to assess test-retest reliability of the candidate items. Bolt-on item selection will consider both the qualitative and quantitative evidence gathered. This protocol outlines a comprehensive mixed-methods process for identifying, developing, selecting and testing bolt-on items that are relevant and culturally appropriate in China. This study may serve as a guide for similar initiatives in other cultural contexts.

ETHICS AND DISSEMINATION

This study received ethics approval from the Institutional Review Board of School of Public Health, Fudan University (IRB number: 2022-TYSQ-03-154). Study findings will be disseminated through international peer-reviewed journal articles as well as public, academic presentations at national and international conferences.

A Direct Comparison of the Measurement Properties of EQ-5D-5L, PROMIS-29+2 and PROMIS Global Health Instruments and EQ-5D-5L and PROPr Utilities in a General Population Sample

OBJECTIVES

We aimed to compare measurement properties of the 5-level version of EQ-5D (EQ-5D-5L) and 2 Patient-Reported Outcomes Measurement Information System (PROMIS) short forms, PROMIS-29+2 and PROMIS Global Health (PROMIS-GH-10), and of EQ-5D-5L and PROMIS-preference scoring system (PROPr) utilities.

METHODS

A cross-sectional survey was conducted in a general population sample in Hungary (N = 1631). We compared the following measurement properties at the level of items, domains, and utilities, the latter using corresponding US value sets: ceiling and floor, informativity (Shannon's indices), agreement, convergent, and known-group validity. For the analyses, PROMIS items/domains were matched to EQ-5D-5L domains that cover similar concepts of health.

RESULTS

The majority of PROMIS items showed enhanced distributional characteristics, including lower ceilings and higher informativity than the EQ-5D-5L. Good convergent validity was established between EQ-5D-5L and PROMIS domains capturing similar aspects of health. Mean EQ-5D-5L utilities were substantially higher than those of PROPr (0.864 vs 0.535). EQ-5D-5L utilities correlated moderately or strongly with PROPr (r = 0.61), PROMIS-GH-10 physical (r = 0.68), and mental health summary scores (r = 0.53). EQ-5D-5L utilities decreased with age, whereas PROPr utilities slightly increased with age. EQ-5D-5L utilities discriminated significantly better in 12/28 (ratio of F-statistics) and 18/26 (area under the receiver-operating characteristics curve ratio) known groups defined by age, self-perceived health status, and self-reported physician-diagnosed health conditions, including hypertension, diabetes, coronary heart disease, chronic kidney disease, and stroke.

CONCLUSIONS

This study provides comparative evidence on the measurement properties of EQ-5D-5L, PROMIS-29+2, and PROMIS-GH-10 and informs decisions about the choice of instruments in population health surveys for assessment of patients' health and for cost-utility analyses.

Psychometric performance of the Chichewa versions of the EQ-5D-Y-3L and EQ-5D-Y-5L among healthy and sick children and adolescents in Malawi

OBJECTIVES

The EuroQol Group has developed an extended version of the EQ-5D-Y-3L with five response levels for each of its five dimensions (EQ-5D-Y-5L). The psychometric performance has been reported in several studies for the EQ-5D-Y-3L but not for the EQ-5D-Y-5L. This study aimed to psychometrically evaluate the EQ-5D-Y-3L and EQ-5D-Y-5L Chichewa (Malawi) versions.

METHODS

The EQ-5D-Y-3L, EQ-5D-Y-5L and PedsQL™ 4.0 Chichewa versions were administered to children and adolescents aged 8-17 years in Blantyre, Malawi. Both of the EQ-5D-Y versions were evaluated for missing data, floor/ceiling effects, and validity (convergent, discriminant, known-group and empirical).

RESULTS

A total of 289 participants (95 healthy, and 194 chronic and acute) self-completed the questionnaires. There was little problem with missing data (< 5%) except in children aged 8-12 years particularly for the EQ-5D-Y-5L. Ceiling effects was generally reduced in moving from the EQ-5D-Y-3L to the EQ-5D-Y-5L. For both EQ-5D-Y-3L and EQ-5D-Y-5L, convergent validity tested with PedsQL™ 4.0 was found to be satisfactory (correlation ≥ 0.4) at scale level but mixed at dimension /sub-scale level. There was evidence of discriminant validity (p > 0.05) with respect to gender and age, but not for school grade (p < 0.05). For empirical validity, the EQ-5D-Y-5L was 31-91% less efficient than the EQ-5D-Y-3L at detecting differences in health status using external measures.

CONCLUSIONS

Both versions of the EQ-5D-Y-3L and EQ-5D-Y-5L had issues with missing data in younger children. Convergent validity, discriminant validity with respect to gender and age, and known-group validity of either measures were also met for use among children and adolescents in this population, although with some limitations (discriminant validity by grade and empirical validity). The EQ-5D-Y-3L seems particularly suited for use in younger children (8-12 years) and the EQ-5D-Y-5L in adolescents (13-17 years). However, further psychometric testing is required for test re-test reliability and responsiveness that could not be carried out in this study due to COVID-19 restrictions.

Examining the psychometric properties of a split version of the EQ-5D-5L anxiety/depression dimension in patients with anxiety and/or depression

PURPOSE

This study explored differences in self-reported responses and the psychometric performance of the composite EQ-5D-5L anxiety/depression (A/D) dimension compared with a split version of the dimension where 'anxiety' and 'depression' are measured separately.

METHODS

People with anxiety and/or depression who visited the Amanuel Mental Specialized Hospital in Ethiopia completed the standard EQ-5D-5L with the added subdimensions. Correlation analysis was used to examine convergent validity with validated measures of depression (PHQ-9) and anxiety (GAD-7), while ANOVA was used to assess known-groups' validity. Agreement between ratings for composite and split dimensions was compared using percent agreement and Cohen's Kappa, while the proportion of 'no problems' reports was compared using the chi-square test. Discriminatory power analysis was undertaken using the Shannon index (H') and Shannon Evenness index (J'). Open-ended questions explored participants' preferences.

RESULTS

Of the 462 respondents, 30.5% reported no problems with the composite A/D, while 13.2% reported no problems on both subdimensions. Agreement between ratings for composite and split dimensions was highest for respondents with comorbid anxiety and depression. The depression subdimension had higher correlation with PHQ-9 (r = 0.53) and GAD-7 (r = 0.33) than the composite A/D dimension (r = 0.36 and r = 0.28, respectively). The split subdimensions and composite A/D could adequately differentiate respondents based on their severity of anxiety or depression. Slightly better informativity was observed in EQ-4D-5L + anxiety (H' = 5.4; J' = 0.47) and EQ-4D-5L + depression (H' = 5.31; J' = 0.46) than EQ-5D-5L (H' = 5.19; J' = 0.45).

CONCLUSIONS

Adopting two subdimensions within the EQ-5D-5L tool appears to perform slightly better than the standard EQ-5D-5L.

A head-to-head comparison of the EQ-5D-5L and 15D descriptive systems and index values in a general population sample

BACKGROUND

The EQ-5D-5L and 15D are generic preference-accompanied health status measures with similar dimensions. In this study, we aim to compare the measurement properties of the EQ-5D-5L and 15D descriptive systems and index values in a general population sample.

METHODS

In August 2021, an online cross-sectional survey was conducted in a representative adult general population sample (n = 1887). The EQ-5D-5L and 15D descriptive systems and index values were compared in terms of ceiling and floor, informativity (Shannon's Evenness index), agreement, convergent and known-groups validity for 41 chronic physical and mental health conditions. Danish value sets were used to compute index values for both instruments. As a sensitivity analysis, index values were also estimated using the Hungarian EQ-5D-5L and Norwegian 15D value sets.

RESULTS

Overall, 270 (8.6%) and 1030 (3.4*10^-6%) unique profiles occurred on the EQ-5D-5L and 15D. The EQ-5D-5L dimensions (0.51-0.70) demonstrated better informativity than those of 15D (0.44-0.69). EQ-5D-5L and 15D dimensions capturing similar areas of health showed moderate or strong correlations (0.558-0.690). The vision, hearing, eating, speech, excretion and mental function 15D dimensions demonstrated very weak or weak correlations with all EQ-5D-5L dimensions, which may indicate potential room for EQ-5D-5L bolt-ons. The 15D index values showed lower ceiling than the EQ-5D-5L (21% vs. 36%). The mean index values were 0.86 for the Danish EQ-5D-5L, 0.87 for the Hungarian EQ-5D-5L, 0.91 for the Danish 15D and 0.81 for the Norwegian 15D. Strong correlations were found between the index values (Danish EQ-5D-5L vs. Danish 15D 0.671, Hungarian EQ-5D-5L vs. Norwegian 15D 0.638). Both instruments were able to discriminate between all chronic condition groups with moderate or large effect sizes (Danish EQ-5D-5L 0.688-3.810, Hungarian EQ-5D-5L 1.233-4.360, Danish 15D 0.623-3.018 and Norwegian 15D 1.064-3.816). Compared to the 15D, effect sizes were larger for the EQ-5D-5L in 88-93% of chronic condition groups.

CONCLUSIONS

This is the first study to compare the measurement properties of the EQ-5D-5L and 15D in a general population sample. Despite having 10 fewer dimensions, the EQ-5D-5L performed better than the 15D in many aspects. Our findings help to understand the differences between generic preference-accompanied measures and support resource allocation decisions.

Comparing the psychometric properties of the EQ-5D-3L and EQ-5D-5L descriptive systems and utilities in atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a common chronic inflammatory skin disorder affecting up to 10% of adults. The EQ-5D is the most commonly used generic preference-accompanied measure to generate quality-adjusted life years (QALYs) for economic evaluations.

OBJECTIVES

We aimed to compare psychometric properties of the three-level and five-level EQ-5D (EQ-5D-3L and EQ-5D-5L) in adult patients with AD.

METHODS

In a multicentre cross-sectional study, 218 AD patients with a broad range of severity completed the EQ-5D-3L, EQ-5D-5L, Dermatology Life Quality Index (DLQI) and Skindex-16. Disease severity outcomes included the Investigator Global Assessment, Eczema Area and Severity Index and the objective SCORing Atopic Dermatitis.

RESULTS

A good agreement was established between the two EQ-5D versions with an intraclass correlation coefficient of 0.815 (95% CI 0.758-0.859, p < 0.001). Overall, 33 different health state profiles occurred in the EQ-5D-3L and 84 in the EQ-5D-5L. Compared to the EQ-5D-3L, ceiling effect was reduced for the mobility, self-care, usual activities and pain/discomfort dimensions by 4.6-11.5%. EQ-5D-5L showed higher average relative informativity (Shannon's evenness index: 0.64 vs. 0.59). EQ-5D-5L demonstrated better convergent validity with EQ VAS, DLQI and Skindex-16. The two measures were similar in distinguishing between groups of patients based on disease severity and skin-specific quality of life with a moderate or large effect size (η² = 0.083-0.489).

CONCLUSION

Both instruments exhibited good psychometric properties in AD; however, the EQ-5D-5L was superior in terms of ceiling effects, informativity and convergent validity. We recommend the use of the EQ-5D-5L to measure health outcomes in clinical settings and for QALY calculations in AD.

Psychometric properties of the EQ-5D-5L compared with EQ-5D-3L in cancer patients in Iran

Background and Objective

Psychometric evidence to support the validity and reliability of the EuroQol-5 Dimensions (EQ-5D) in cancer patients is limited. This study aimed to test the validity and reliability of the EQ-5D-5L (5L) in comparison with EQ-5D-3L (3L) in cancer patients.

Methods

Data of 650 cancer patients were collected through consecutive sampling method from three largest governmental cancer centers in Iran between June 2021 and January 2022. The data were gathered using the 3L, 5L, and the European Organization for Research and Treatment of Cancer quality of life questionnaire (QLQ-C30) instruments. The 3L and 5L were compared in terms of ceiling effect, discriminatory power, convergent and known-groups validity, relative efficiency, inconsistency, agreement, and reliability.

Results

Compared with the 3L, ceiling effect decreased by 27.86%. Absolute and relative informativity of discriminatory power improved by 45.93% and 22.92% in the 5L, respectively. All convergent validity coefficients with 5L were stronger than with 3L. Both 3L and 5L demonstrated good known-groups validity, and the relative efficiency was higher for 5L in 4 out of 7 patients' characteristics. The two instruments showed low overall inconsistency (1.45%) and 92.57% of the differences of observations between the 3L and 5L were within the 95% limit of agreement. The interclass correlation coefficient (ICC) for 3L and 5L indexes were 0.88 and 0.85, respectively, and kappa coefficients in the 3L dimensions (range=0.66-0.92) were higher than the 5L(range=0.64-0.79).

Conclusions

The 5L demonstrated to be better than the 3L in terms of ceiling effect, inconsistency, discriminatory power, convergent validity, relative efficiency.

What is measured by the composite, single-item pain/discomfort dimension of the EQ-5D-5L? An exploratory analysis

PURPOSE

This study examines the EQ-5D-5L pain/discomfort dimension by drawing comparisons with five other pain and discomfort items (pain severity, discomfort severity, pain frequency, discomfort frequency and pain interference) collected in the Australian psychometric study for the EQ Health and Wellbeing instrument.

METHODS

Participants, recruited via a market research company, completed an online survey. Methods of analyses included the assessment of descriptive statistics, variation in reporting patterns using chi-square tests and cross-tabulations, correlation analyses, ordered univariate logistic regression, and discriminatory power analyses (Shannon index (H') and Shannon Evenness index (J')).

RESULTS

Survey data from 514 participants were used. Compared with EQ-5D-5L pain/discomfort, there was a higher proportion of respondents reporting some level of impairment on at least one of the pain severity and discomfort severity items (74% versus 81%). Correlation with EQ-5D-5L pain/discomfort was strongest for pain severity (r = 0.83) and weakest for discomfort frequency (r = 0.41); the same inferences were drawn for predictive ability. Adding any additional pain or discomfort items to the EQ-5D-5L increased the absolute informativity (H') but not the relative informativity (J'). When replacing EQ-5D-5L pain/discomfort with separate pain and/or discomfort items - i.e., adding items to a modified 'EQ-4D-5L'-absolute informativity increased, while relative informativity increased only when pain interference and frequency-related items (independently or in combination) were added.

CONCLUSION

The EQ-5D-5L pain/discomfort dimension captures aspects of pain more than aspects of discomfort. Potential reasons include the absence of descriptors or because pain is mentioned first in the composite item.

Health-related quality of life in patients with lower limb amputation - an assessment of the measurement properties of EQ-5D-3L and EQ-5D-5L using data from the Swedish Amputation and Prosthetics Registry

PURPOSE

To assess the measurement properties of EQ-5D-3L and EQ-5D-5L in patients with a major lower limb amputation (LLA).

METHODS

This was a retrospective register-based study using data from the Swedish Amputation and Prosthetics Registry (SwedeAmp). Patients with a six-months follow-up (including either EQ-5D-3L or EQ-5D-5L) after a major unilateral LLA were included. The measurement properties of EQ-5D-3L and EQ-5D-5L were compared in terms of feasibility, response patterns, informativity, and convergent and known-group validity.

RESULTS

The sample included 700 patients with below-knee amputation (76%), above-knee amputation (18%), or knee disarticulation (7%). Responses to EQ-5D-3L and -5L were similar regarding feasibility (98% completion rate) and the proportion reporting no problems (7% and 6%). Compared to EQ-5D-3L, EQ-5D-5L showed higher absolute and relative informativity in all dimensions, with the largest improvement in the mobility dimension. In the analyses of convergent validity, the EQ-5D-5L generally showed stronger correlations with disease-specific measures. Only EQ-5D-5L was able to discriminate between subgroups with different amputation levels.

CONCLUSION

The findings support the use of EQ-5D-5L over EQ-5D-3L in patients with an LLA, mainly due to improved informativity and improved convergent and known-group validity.Implications for rehabilitationThe measurement properties of two EQ-5D versions, EQ-5D-3L and EQ-5D-5L, has so far not been evaluated in patients with a lower limb amputation (LLA)The results support the use of EQ-5D-5L over the use of EQ-5D-3L, mainly due to improved informativity and stronger correlations with disease-specific patient-reported outcome measuresThe five-level version of EQ-5D is recommended for future applications of EQ-5D in clinical outcome studies, health economic evaluations, and in the routine follow-up of patients with a major LLAIn the early rehabilitation process six months after an LLA, the majority of patients reported problems with mobility, pain/discomfort, and usual activities.

The performance of the EQ-5D-Y-5L compared to the EQ-5D-Y-3L in children and adolescents with cerebral palsy (CP)

Objectives

The aim of this study is to compare the performance and validity of the EQ-5D-Y-3L (Y-3L) and EQ-5D-Y-5L (Y-5L) in South African children and adolescents with cerebral palsy (CP).

Methods

Children/adolescents with CP and those from the general population completed the Y-5L, Y-3L, and PedsQL. Physiotherapists at the school classified participants' functional ability on the Gross Motor Functioning Classification System (GMFCS).

Results

Fifty-one children/adolescents completed the measures. The ceiling effect had a 44% relative reduction for Mobility and floor effects decreased across all dimensions except for Looking After Myself when moving from the Y-3L to Y-5L. Informativity of dimensions improved on average by 0.27 on the Y-5L with similar evenness. There was a range of 6-16% inconsistent responses when moving from the Y-3L to the Y-5L. Convergent validity was strong on paired Y-3L and Y-5L dimensions: Kendall's Tau B (range 0.53 - 0.85) and Gamma (range 0.79 - 0.99). There was significant moderate association between Y-3L and Y-5L with similar items on the PedsQL. The physical dimensions of Mobility, Looking After Myself and Usual Activities were significantly associated with GMFCS with those having less independent mobility reporting more severe problems on dimension scores.

Conclusion

The Y-5L showed a notable reduction in ceiling and floor effects, improved discriminatory power, higher criterion validity with the GMFCS and similar concurrent validity with the PedsQL as the Y-3L. It is recommended that the Y-5L is further tested for reliability and responsiveness in this population group so that its utility for detecting change in clinical trials or as a routine outcome measure can be determined.

Psychometric performance of proxy-reported EQ-5D youth version 5-level (EQ-5D-Y-5L) in comparison with three-level (EQ-5D-Y-3L) in children and adolescents with scoliosis

OBJECTIVES

To assess the psychometric performance of proxy-reported EQ-5D-Y-5L (Y-5L) in comparisons with EQ-5D-Y-3L (Y-3L) administered by caregivers of patients with juvenile (JIS) or adolescent idiopathic scoliosis (AIS).

METHODS

A consecutive sample of caregivers of JIS or AIS patients were recruited. Redistribution property, ceiling effects, and discriminative power were examined. Known-group validity was determined by examining their ability to detect differences across clinical known groups. Test-retest reliability was assessed using intraclass correlation coefficient (ICC) for EQ-VAS score and Gwet's agreement coefficient (GAC) and percentage agreement (PA) for dimension responses. Furthermore, subgroups were analyzed for comparing test-retest reliability.

RESULTS

A total of 130 caregivers were involved in the study. Consistencies between proxy-reported Y-3L and Y-5L were very high for all dimensions (93.8-99.2%). The ceiling effect in the Y-5L was slightly reduced in four dimensions (AR: 0.8-2.3%) whereas increased in "Having pain/discomfort". Greater informativity was found in the Y-5L than the Y-3L. In known-group comparisons of curvature magnitude, curvature type, and treatment modality, Y-5L and Y-3L dimension scales showed hypothesized results. For example, more full-health responses were found in the mild Cobb angle group (Y-5L: 63.1%; Y-3L: 62.2%) than the severe Cobb angle group (Y-5L: 55.6%, Y-3L: 55.6%). EQ-VAS score exhibited low test-retest reliability (ICC: 0.41), whereas dimension scales of both instruments showed satisfactory test-retest reliability (GAC ≥ 0.7 and PA ≥ 70% for all). In most known groups, hard-to-observe dimensions were more reliable for proxy-reported Y-5L than Y-3L.

CONCLUSION

Both the proxy-reported Y-5L and Y-3L are valid and reliable instruments for assessing the HRQoL of JIS or AIS patients.

Comparing the psychometric properties of EQ-5D-3L and EQ-5D-5L proxy ratings by informal caregivers and a health professional for people with dementia

Background

Assessing health-related quality of life (HRQoL) among persons with dementia poses several challenges due to cognitive decline and limited perception. As a result, proxy ratings by family members or health professionals are used. The EQ-5D is the most commonly used generic and preference-based HRQoL instrument. Methodological drawbacks of the three-level version (EQ-5D-3L) prompted the development of the five-level version (EQ-5D-5L) by expanding the range in the domains. However, no comparison of the psychometric properties of both versions and different proxy ratings exist so far. Therefore, the objective of this study was to compare the psychometric properties of the EQ-5D-5L and EQ-5D-3L by application of different proxy ratings in dementia.

Methods

The EQ-5D-3L and -5L were completed by n = 52 family caregivers and one care manager at baseline and three and six months later. In total, 106 caregiver and 133 care manager proxy ratings were completed. The EQ-5D-3L and 5L were evaluated in terms of acceptability (missing values), agreement, ceiling effects, redistribution properties and inconsistency, and informativity (Shannon, H', and Shannon Evenness, J', indices) as well as convergent and discriminative validity.

Results

Mean proxy index scores were higher for the 5L than the 3L. Missing values occurred less frequently in both proxy ratings and versions (< 1%). Agreement between both measures was high but higher in caregiver than care-manager ratings (ICC 0.885 vs. 0.840). The relative ceiling effect decreased from the 3L to the 5L, more intensively in the care-manager (75%) than the caregiver rating (56%). Inconsistency between both versions was low. Informativity increased from the 3L to the 5L version, nearly equally in both proxy ratings. The 5L also demonstrated a better discriminative ability and convergent validity than the 3L, especially in the caregiver rating.

Conclusion

Compared to the EQ-5D-3L, the EQ-5D-5L had higher feasibility and acceptability and was slightly superior by a reduction of ceiling effects and an improvement in informativity, discriminative ability and convergent validity. Proxy ratings by informal caregivers overall demonstrated better psychometric properties than professional care-manager ratings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12955-022-02049-y.

Measurement properties and responsiveness of the EQ-5D-Y-5L compared to the EQ-5D-Y-3L in children and adolescents receiving acute orthopaedic care

Objective

The aim of this study is a head-to-head comparison of the instrument performance and responsiveness of the EQ-5D-Y-3L and the expanded English version of the EQ-5D-Y-5L in children/adolescents receiving acute orthopaedic management in South Africa.

Methods

Children/adolescents aged 8–15 years completed the EQ-5D-Y-5L, EQ-5D-Y-3L, self-rated health (SRH) question and PedsQL at baseline. The EQ-5D-Y-5L, EQ-5D-Y-3L and SRH question were repeated after 24 and 48 h. Performance of the EQ-5D-Y-5L and EQ-5D-Y-3L was determined by comparing feasibility (missing responses), redistribution of dimensions responses, discriminatory power, concurrent validity, and responsiveness.

Results

Eighty-three children/adolescents completed baseline measures and seventy-one at all three time-points. Reporting of 11111 decreased by 20% from the EQ-5D-Y-3L to the EQ-5D-Y-5L. Informativity of dimensions improved on average by 0.267 on the EQ-5D-Y-5L with similar evenness. There was a range of 11–27% inconsistent responses when moving from the EQ-5D-Y-3L to the EQ-5D-Y-5L. There was a low to moderate and significant association on the EQ-5D-Y-3L and EQ-5D-Y-5L to similar items on the PedsQL and SRH scores. Percentage change over time was greater for the EQ-5D-Y-5L (range 0–182%) than EQ-5D-Y-3L (range 0–100%) with the largest reduction for both measures between 0 and 48 h. For those who respondents who showed an improved SRH the EQ-5D-Y-5L and EQ-5D-Y-3L showed significant paired differences.

Conclusion

The English version of the EQ-5D-Y-5L appears to be a valid and responsive extension of the EQ-5D-Y-3L for children receiving acute orthopaedic management. The expanded levels notably reduce the ceiling effect and has greater discriminatory power. Concurrent validity of the EQ-5D-Y-3L and EQ-5D-Y-5L was low to moderate with similar PedsQL items and SRH. The EQ-5D-Y-5L generally showed greater change than the EQ-5D-Y-3L across all dimensions with the greatest change observed for 0–48 h. Responsiveness was comparable across the EQ-5D-Y-3L and EQ-5D-Y-5L for those with improved SRH. Greater sensitivity to change may be observed on comparison of utility scores, once preference-based value sets are available for the EQ-5D-Y-5L.

Adding a fatigue item to the EQ-5D-5L improves its psychometric performance in the general population

Background

Fatigue is a common and often disturbing sequela of serious chronic health conditions. In the widely applied HRQL instrument, the EQ-5D, this aspect is not included directly, for its assumed lack of additional information. We investigated the validity of this assumption by determining the gain—if any—of an additional fatigue item to the EQ-5D-5L in a general population sample.

Methods

A Dutch general population sample (including diseased people) completed a web-based survey including the EQ-5D-5L and the Rivermead Post-Concussion Symptoms Questionnaire (RPQ). The RPQ fatigue item was used to create the EQ-5D-5L + Fatigue. We head-to-head compared the psychometric performance contrasting the EQ-5D-5L and EQ-5D-5L + Fatigue: distribution (e.g. ceiling), informativity cf. Shannon's indices, convergent validity, domain dependency, and explanatory power. Results were compared between subgroups with and without ≥ 1 chronic health condition.

Results

The study population consisted of 3027 persons of whom 52% had a chronic health condition. The mean EQ-5D-5L utility score was 0.83 and 48% experienced some degree of fatigue. Adding the fatigue item to the EQ-5D-5L decreased the ceiling effect, increased absolute informativity (Hʹ = 6.44 vs. Hʹ = 4.90) and relative informativity (Jʹ = 0.46 vs. Jʹ = 0.42). The extra fatigue item slightly increased convergent validity (Spearman’s rank correlation coefficient = − 0.61 vs. − 0.62). Domain dependency analysis showed that all EQ-5D-5L domains are dominant over the fatigue item. Explanatory power of the EQ-5D-5L + Fatigue was higher compared to the EQ-5D-5L (R² = 0.42 vs. 0.39). The gain is substantially larger in the subgroup with chronic health conditions.

Conclusions

Adding a fatigue item to the EQ-5D-5L improved all psychometric performance criteria of the enriched instrument in the general population. Effects are substantially larger in the subgroup with chronic health conditions, indicating that adding a fatigue item to the EQ-5D-5L is especially relevant in evaluating the HRQL of diseased people.

Comparison of the Psychometric Properties of the EQ-5D-3L-Y and EQ-5D-5L-Y Instruments in Spanish Children and Adolescents

OBJECTIVES

The study aimed to assess the reliability and validity of EQ-5D-5L-Y and to compare the performance of EQ-5D-5L-Y with EQ-5D-3L-Y in children and adolescents.

METHODS

The Spanish versions of the 3L and 5L of EQ-5D for youths, were administered to children and adolescents from the general population. Feasibility and reliability were determined for the EQ-5D-5L-Y. The EQ-5D-5L-Y and EQ-5D-3L-Y were evaluated in terms of ceiling effects, informativity, and correlations with other generic measurements of health-related quality of life.

RESULTS

A total of 714 healthy children and adolescents (10.7 ± 2.1 years old) from the general population participated in the study. Most of the sample reported full health status. The feasibility and reliability for the EQ-5D-5L-Y were acceptable, but the questionnaire showed a low convergent validity. Absolute informativity (Shannon index) showed a slight increase in all dimensions of the 5L compared with the 3L; nevertheless, there were only statistically significant differences between 5L and 3L in the dimension "feeling worried, sad, or unhappy" and also on the overall system. Relative informativity (Shannon evenness index) showed a decrease in the 5L compared with 3L for all dimensions, except for "looking after myself." Correlations with other health measurements, in both 3L and 5L, showed similar results to those observed in the international EQ-5D-3L-Y validation study.

CONCLUSION

The results show that EQ-5D-5L-Y is feasible, consistent, and reliable, but there are minor differences in the ceiling effect and informativity between the EQ-5D-5L-Y and EQ-5D-3L-Y versions in the general population.

A comparative study on the measurement properties of Dermatology Life Quality Index (DLQI), DLQI-Relevant and Skindex-16

BACKGROUND

Dermatology Life Quality Index (DLQI) and Skindex-16 are among the most commonly used dermatology-specific health-related quality-of-life (HRQoL) instruments. DLQI has two common scoring methods, the original and the DLQI-Relevant (DLQI-R) modification. Head-to-head comparisons of the measurement properties of the DLQI, DLQI-R and Skindex-16 are currently lacking.

OBJECTIVES

We aim to compare the measurement properties of the DLQI, DLQI-R and Skindex-16.

METHODS

We analysed data from 618 patients with self-reported physician-diagnosed dermatological conditions from a cross-sectional survey carried out in Hungary in early 2020. DLQI, DLQI-R and Skindex-16 were compared in terms of ceiling and floor effects, informativity, convergent validity and known-group validity.

RESULTS

Mean DLQI, DLQI-R and Skindex-16 total scores were 3·76 ± 5·03, 4·11 ± 5·34 and 29·36 ± 26·62, respectively. Among patients with a DLQI/DLQI-R total score of zero, 64% reported problems on Skindex-16. Overall, 23-38% of patients with 'not relevant' responses on DLQI items 3 (shopping/home/gardening), 7 (working/studying), 8 (interpersonal problems) and 9 (sexual difficulties) reported problems on their corresponding Skindex-16 items. Average relative informativity (Shannon's evenness index) was the highest for Skindex-16 (0·85), followed by DLQI-R (0·66) and DLQI (0·54). DLQI, DLQI-R and Skindex-16 demonstrated similar convergent validity. DLQI was able to better discriminate between known groups of patients based on overall skin-related HRQoL impairment, whereas DLQI-R and Skindex-16 performed better with respect to self-perceived health status.

CONCLUSIONS

Skindex-16 seems to be more sensitive than DLQI/DLQI-R in capturing mild impairment in HRQoL. Our findings help to provide a fuller understanding of the difference between DLQI, DLQI-R and Skindex-16 and support the informed choice of instrument for clinical and research purposes.

Comparison of the EQ-5D-5L and the EQ-5D-3L using individual patient data from the REFORM trial

Background: This study compares the 5-level version of the EQ-5D (5L) with the 3-level version EQ-5D (3L) in older adults using individual patient data from the REFORM (REducing Falls with Orthoses and a Multifaceted podiatry intervention) trial. Methods: EQ-5D-5L and EQ-5D-3L were administered to men and women (n=151) over the age of 65 years alongside the REFORM trial. The two versions of the EQ-5D were assessed in terms of feasibility, level of consistency, ceiling effect and discriminatory power. We also undertook a comparison of the performance of different EQ-5D-3L and EQ-5D-5L value sets. Results: The proportion of participants that returned a complete questionnaire was higher for the 5L (96.7%) than for the 3L (92.7%). Missing values among dimensions were on average 1.59% (5L) and 1.45% (3L). The ceiling effect was reduced from 18.2% (3L) to 6% (5L). On average the proportion of inconsistent responses between both descriptive systems was 3.25%. Redistribution from 3L to 5L showed valid results for the majority of consistent level combinations, with slight inconsistency in the case of Anxiety/Depression. For the 5L, 67 unique health states were observed for the 5L compared to 27 for the 3L. The absolute informatively improved with the new classification system (5.48 for 5L versus 3.91 for 3L) and relative discriminatory power improved slightly on average (0.90 for 5L versus 0.84 for 3L). The mean difference between the EQ-5D-5L and EQ-5D-3L values was 0.091 (range -0.345 to 0.505); whilst the mean difference between the EQ-5D-5L and the crosswalk values was 0.082 (range -0.035 to 0.293). Conclusion: In the REFORM clinical trial involving an elderly population, our study supported the feasibility and convergent validity of both EQ-5D-3L and EQ-5D-5L. Results suggest that the 5L improves the ceiling effect and discriminatory power. The EQ-5D-5L scores were significantly higher than both EQ-5D-3L and crosswalk.

Psychometric Properties of EQ-5D-3L and EQ-5D-5L in Cognitively Impaired Patients Living with Dementia

BACKGROUND

Assessing health-related quality of life in dementia poses challenges due to patients' cognitive impairment. It is unknown if the newly introduced EQ-5D five-level version (EQ-5D-5L) is superior to the 3-level version (EQ-5D-3L) in this cognitively impaired population group.

OBJECTIVE

To assess the psychometric properties of the EQ-5D-5L in comparison to the EQ-5D-3L in patients living with dementia (PwD).

METHODS

The EQ-5D-3L and EQ-5D-5L were assessed via interviews with n = 78 PwD at baseline and three and six months after, resulting in 131 assessments. The EQ-5D-3L and EQ-5D-5L were evaluated in terms of acceptability, agreement, ceiling effects, redistribution properties and inconsistency, informativity as well as convergent and discriminative validity.

RESULTS

Mean index scores were higher for the EQ-5D-5L than the EQ-5D-3L (0.70 versus 0.64). Missing values occurred more frequently in the EQ-5D-5L than the EQ-5D-3L (8%versus 3%). Agreement between both measures was acceptable but poor in PwD with moderate to severe cognitive impairment. The index value's relative ceiling effect decreased from EQ-5D-3L to EQ-5D-5L by 17%. Inconsistency was moderate to high (13%). Absolute and relative informativity increased in the EQ-5D-5L compared to the 3L. The EQ-5D-5L demonstrated a lower discriminative ability and convergent validity, especially in PwD with moderate to severe cognitive deficits.

CONCLUSION

The EQ-5D-5L was not superior as a self-rating instrument due to a lower acceptability and discriminative ability and a high inconsistency, especially in moderate to severe dementia. The EQ-5D-3L had slightly better psychometric properties and should preferably be used as a self-rating instrument in economic evaluations in dementia.

Developing and testing a cognitive bolt-on for the EQ-5D-Y (Youth)

Purpose

The aim of this study was to develop and test a cognitive dimension as a bolt-on for the German version of the EQ-5D-Y (Youth).

Methods

A literature review and six focus groups with children and adolescents were used to develop the cognitive dimension for the EQ-5D-Y. In a two-phase pretest, the acceptability, feasibility and performance of this dimension were assessed (phase 1: qualitative face-to-face interviews, phase 2: standard pretest in a clinical setting). In total, 280 children and adolescents participated in this study.

Results

School performance, concentration, memory and learning ability represent the most important components of cognitive functioning in children and adolescents. Hence, those components were incorporated into the cognitive dimension of the EQ-5D-Y by adding four items. For children and adolescents living with a rheumatic disorder or type 1 diabetes mellitus, the EQ-5D-Y plus a cognitive bolt-on demonstrated good acceptability, feasibility and performance. The cognitive items improved the explanatory power for the EQ visual analogue scale (EQ-VAS). Factor analysis has shown that a reduction of the cognitive bolt-on into one or two item(s) is justifiable.

Conclusion

By enhancing the EQ-5D-Y with a cognitive bolt-on, we developed an instrument that incorporates current findings on Health-Related Quality of Life (HRQoL) and is suitable for the target population. Empirical results of this study show that cognitive functioning is an important part of HRQoL assessment in children and adolescents. The inclusion of a cognitive dimension in the EQ-5D-Y improves the HRQoL measurement.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11136-021-02899-x.

Psychometric properties of the Polish version of SF-12v2 in the general population survey

Background: This study aimed to assess the psychometric properties of the SF-12 questionnaire (in comparison to the EQ-5D questionnaire also), based on a survey conducted on a sample representing the general population of Poland.Methods: The respondents completed Polish versions of health-related quality of life (HRQoL) questionnaires: SF-12, EQ-5D-5L, EQ VAS, and EQ-5D-3L, together with demographic and socioeconomic characteristic items. The following psychometric properties were analyzed: informativity power, ceiling and floor effects, reliability, and construct validity. We also conducted an exploratory factor analysis.Results: A total of 3,896 respondents (mean age 48.3 years, 53.2% female) were included in the analysis. The results showed exceptional informativity power of SF-12 items. We did not observe any ceiling and floor effects for the PCS and MCS components. The high values of the Cronbach's alpha coefficients confirmed the reliability of SF-12. Our hypothesis about lower scores for the summary components among older respondents, females and patients having declared diabetes was confirmed. The results of factor analysis also provided evidence for a positive assessment of construct validity.Conclusions: Our results confirmed that the Polish version of the SF-12 questionnaire is a valid instrument for use in HRQoL assessment among the general population of Poland.

The measurement performance of the EQ-5D-5L versus EQ-5D-3L in patients with hidradenitis suppurativa

PURPOSE

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease that affects up to 1% of the population in Europe. The EQ-5D is the most commonly used generic instrument for measuring health-related quality of life among HS patients. This study aims to compare the measurement properties of the two adult versions of EQ-5D (EQ-5D-3L and EQ-5D-5L) in patients with HS.

METHODS

We recruited 200 consecutive patients with HS (mean age 37 years, 38% severe or very severe HS) to participate in a multicentre cross-sectional survey. Patients completed the EQ-5D-3L, EQ-5D-5L, Dermatology Life Quality Index (DLQI) and Skindex-16 questionnaires.

RESULTS

More than twice as many different health state profiles occurred in the EQ-5D-5L compared to the EQ-5D-3L (101 vs. 43). A significant reduction in ceiling effect was found for the mobility, self-care and usual activities dimensions. A good agreement was established between the EQ-5D-3L and EQ-5D-5L with an intraclass correlation coefficient of 0.872 (95% CI 0.830-0.903; p < 0.001) that was confirmed by a Bland-Altman plot. EQ-5D-5L improved both the absolute and relative informativity in all dimensions except for anxiety/depression. EQ-5D-3L and EQ-5D-5L demonstrated similar convergent validity with DLQI and Skindex-16. EQ-5D-5L was able to better discriminate between known groups of patients based on the number of comorbidities and disease severity (HS-Physician's Global Assessment).

CONCLUSION

In patients with HS, the EQ-5D-5L outperformed the EQ-5D-3L in feasibility, ceiling effects, informativity and known-groups validity for many important clinical characteristics. We recommend using the EQ-5D-5L in HS patients across various settings, including clinical care, research and economic evaluations.

Comparing the measurement properties of the EQ-5D-5L and the EQ-5D-3L in hypertensive patients living in rural China

PURPOSE

The purpose of this study was to compare the measurement properties of two versions of EQ-5D (i.e.EQ-5D-3L and EQ-5D-5L) in hypertensive patients in rural China.

METHODS

A cross-sectional survey was carried out in hypertensive patients in rural China. We compared the ceiling effects, redistribution properties, informativity, known-groups validity, and relative efficiency of the 3L and 5L and examined their agreement.

RESULTS

A total of 11,412 patients were enrolled in our study. The mean EQ-5D index score was 0.84 (SD 0.21) according to the 5L and 0.86 (SD 0.17) according to the 3L. A good agreement was observed between the 3L and 5L. The overall ceiling effect decreased from 46.4% (3L) to 29.4% (5L). The Shannon index, H' improved in all dimensions when used 5L. When used 3L, the median responses of all groups were consistent with 5L across the three dimensions of 'mobility', 'self-care', 'usual activities', while the median responses were inconsistent for the 'pain/discomfort' and 'anxiety/depression' dimensions. The 3L performed better in eight comorbidities in terms of F-statistics and six comorbidities in terms of the area under the receiver operating characteristic curves (AUROCs). The 5L performed better both in terms of the F-statistics and AUROCs in age, education level, anti-hypertensive medication use.

CONCLUSION

Taking all comparisons into account, we recommend the EQ-5D-5L for use in patients with hypertension in rural China.

Measurement properties of EQ-5D-3L and EQ-5D-5L in recording self-reported health status in older patients with substantial multimorbidity and polypharmacy

BACKGROUND

The EQ-5D-3L and EQ-5D-5L are two generic health-related quality of life measures, which may be used in clinical and health economic research. They measure impairment in 5 aspects of health: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. The aim of this study was to assess the performance of the EQ-5D-3L and EQ-5D-5L in measuring the self-reported health status of older patients with substantial multimorbidity and associated polypharmacy.

METHODS

Between 2017 and 2019, we administered EQ-5D-3L and EQ-5D-5L to a subset of patients participating in the OPERAM trial at 6 months and 12 months after enrolment. The OPERAM trial is a two-arm multinational cluster randomised controlled trial of structured medication review assisted by a software-based decision support system versus usual pharmaceutical care, for older people (aged ≥ 70 years) with multimorbidity and polypharmacy. In the psychometric analyses, we only included participants who completed the measures in full at 6 and 12 months. We assessed whether responses to the measures were consistent by assessing the proportion of EQ-5D-5L responses, which were 2 or more levels away from that person's EQ-5D-3L response. We also compared the measures in terms of informativity, and discriminant validity and responsiveness relative to the Barthel Index, which measures independence in activities of daily living.

RESULTS

224 patients (mean age of 77 years; 56% male) were included in the psychometric analyses. Ceiling effects reported with the EQ-5D-5L (22%) were lower than with the EQ-5D-3L (29%). For the mobility item, the EQ-5D-5L demonstrated better informativity (Shannon's evenness index score of 0.86) than the EQ-5D-3L (Shannon's evenness index score of 0.69). Both the 3L and 5L versions of EQ-5D demonstrated good performance in terms of discriminant validity, i.e. (out of all items of the EQ-5D-3L and EQ-5D-5L, the pain/discomfort and anxiety/depression items had the weakest correlation with the Barthel Index. Both the 3L and 5L versions of EQ-5D demonstrated good responsiveness to changes in the Barthel Index.

CONCLUSION

Both EQ-5D-3L and EQ-5D-5L demonstrated validity and responsiveness when administered to older adults with substantial multimorbidity and polypharmacy who were able to complete the measures.

Comparing EQ-5D-3L and EQ-5D-5L performance in common cancers: suggestions for instrument choosing

PURPOSE

To compare the performance of three-level EuroQol five-dimensions (EQ-5D-3L) and five-level EuroQol five-dimensions (EQ-5D-5L) among common cancer patients in urban China.

METHODS

A hospital-based cross-sectional survey was conducted in three provinces from 2016 to 2018 in urban China. Patients with breast cancer, colorectal cancer, or lung cancer were recruited to complete the EQ-5D-3L and EQ-5D-5L questionnaires. Response distribution, discriminatory power (indicator: Shannon index [H'] and Shannon evenness index [J']), ceiling effect (the proportion of full health state), convergent validity, and health-related quality of life (HRQoL) were compared between the two instruments.

RESULTS

A total of 1802 cancer patients (breast cancer: 601, colorectal cancer: 601, lung cancer: 600) were included, with the mean age of 55.6 years. The average inconsistency rate was 4.4%. Compared with EQ-5D-3L (average: H' = 1.100, J' = 0.696), an improved discriminatory power was observed in EQ-5D-5L (H' = 1.473, J' = 0.932), especially contributing to anxiety/depression dimensions. The ceiling effect was diminished in EQ-5D-5L (26.5%) in comparison with EQ-5D-3L (34.5%) (p < 0.001), mainly reflected in the pain/discomfort and anxiety/depression dimensions. The overall utility score was 0.790 (95% CI 0.778-0.801) for EQ-5D-3L and 0.803 (0.790-0.816) for EQ-5D-5L (p < 0.001). A similar pattern was also observed in the detailed cancer-specific analysis.

CONCLUSIONS

With greater discriminatory power, convergent validity and lower ceiling, EQ-5D-5L may be preferable to EQ-5D-3L for the assessment of HRQoL among cancer patients. However, higher utility scores derived form EQ-5D-5L may also lead to lower QALY gains than those of 3L potentially in cost-utility studies and underestimation in the burden of disease.

The added value of extending the EQ-5D-5L with an itching item for the assessment of health-related quality of life of burn patients: an explorative study

INTRODUCTION

Health-related quality of life (HRQL) is an important outcome in burn care and research. An advantage of a generic HRQL instrument, like the EQ-5D, is that it enables comparison of outcomes with other conditions and the general population. However, the downside is that it does not include burn specific domains, like scar issues or itching. Adding extra items to a generic instrument might overcome this issue. This study explored the potential and added value of extending the EQ-5D-5L with a burn-specific item, using a itching item as an example.

METHODS

The EQ-5D-5L and the Patient and Observer Scar Assessment Scale (POSAS) was completed by adult patients 5-7 years after injury. A separate POSAS itching item was used to study the added value of an itching item for the EQ-5D-5L. The EQ-5D-5L + Itching was created by adding the POSAS itching item to the EQ-5D-5L. Five psychometric properties were compared between EQ-5D-5L and EQ-5D-5L + Itching: distribution (e.g. ceiling), informativity cf. Shannon's indices, convergent validity, dimension dependency, and explanatory power respectively.

RESULTS

A total of 243 patients were included, of whom 49% reported any itching on the POSAS. Adding an itching item to the EQ-5D-5L decreased the ceiling effect, and resulted in increased absolute informativity (H' = 4.76 vs. H' = 3.64) and relative informativity (J' = 0.34 vs. J' = 0.31). The extra itching item decreased the convergent validity (Spearman's rank correlation coefficient = -0.51 vs. -0.59). Mutual dependency of dimensions existed, showing that all other items were dominant over the itching item. Adding the itching item to the standard EQ-5D-5L barely improved explanatory power (49.3% vs. 49.0%).

CONCLUSIONS

PThe present study showed adding a burn-specific item to the EQ-5D-5L is possible and has potential. However, 5 to 7 years after injury, adding an itching item to the EQ-5D-5L provides little additional information; the gain in terms of added value is relatively small. Apart from instances where itching information is specifically needed, a strong case is not present for adding an itching item to the EQ-5D-5L for long-term (>5 yr after burns) HRQL assessment in burn patients. In early time periods after burn, the added value might be greater and we recommend exploring this potential in future studies, ideally on multiple timepoints after burn.

Comparing the EQ-5D-3 L and EQ-5D-5 L: studying measurement and scores in Indonesian type 2 diabetes mellitus patients

BACKGROUND

The EuroQoL five-dimensional instrument (EQ-5D) is the favoured preference-based instrument to measure health-related quality of life (HRQoL) in several countries. Two versions of the EQ-5D are available: the 3-level version (EQ-5D-3 L) and the 5-level version (EQ-5D-5 L). This study aims to compare specific measurement properties and scoring of the EQ-5D-3 L (3 L) and EQ-5D-5 L (5 L) in Indonesian type 2 diabetes mellitus (T2DM) outpatients.

METHODS

A survey was conducted in a hospital and two primary healthcare centres on Sulawesi Island. Participants were asked to complete the two versions of the EQ-5D instruments. The 3 L and 5 L were compared in terms of distribution and ceiling, discriminative power and test-retest reliability. To determine the consistency of the participants' answers, we checked the redistribution pattern, i.e., the consistency of a participant's scores in both versions.

RESULTS

A total of 198 T2DM outpatients (mean age 59.90 ± 11.06) completed the 3 L and 5 L surveys. A total of 46 health states for 3 L and 90 health states for 5 L were reported. The '11121' health state was reported most often: 17% in the 3 L and 13% in the 5 L. The results suggested a lower ceiling effect for 5 L (11%) than for 3 L (15%). Regarding redistribution, only 6.1% of responses were found to be inconsistent in this study. The 5 L had higher discriminative power than the 3 L version. Reliability as reflected by the index score was 0.64 for 3 L and 0.74 for 5 L. Pain/discomfort was the dimension mostly affected, whereas the self-care dimension was the least affected.

CONCLUSIONS

This study suggests that the 5 L-version of the EQ-5D instrument performs better than the 3 L-version in T2DM outpatients in Indonesia, regarding measurement and scoring properties. As such, our study supports the use of the 5 L as the preferred health-related quality of life measurement tool. We did not do a trial but this study was approved by the Medical Ethics Committee of Universitas Gadjah Mada Yogyakarta, Indonesia (document number KE/FK/1188/EC, 12 November 2014, amended 16 March 2015).

A head-to-head comparison of five-level (EQ-5D-5L-Y) and three-level EQ-5D-Y questionnaires in paediatric patients

PURPOSE

The aim of this study was to assess the psychometric properties of a youth version of the EQ-5D five-level questionnaire (5LY) and its three-level version (3LY) in a sample of Chinese paediatric patients.

METHODS

A consecutive sample of idiopathic scoliosis patients were recruited from a referral outpatient scoliosis center at Hong Kong, China in October 2017 and completed the two versions of EQ-5D-Y. Redistribution properties in each dimension of EQ-5D-Y were analyzed between 5LY and 3LY by logistics regressions. Absolute reduction and relative reduction in ceiling effects from the 3LY to the 5LY were calculated. Test-retest reliability was assessed by examining the Gwet's agreement coefficient (Gwet's AC) for five individual dimension responses over the 2-week period.

RESULTS

A total of 129 idiopathic scoliosis patients completed the two versions of EQ-5D-Y at baseline assessment, among which 70 patients completed the test-retest interview in 2-3 weeks after baseline assessment. For redistribution properties, the proportion of inconsistency was low in all the dimensions, ranging from 0.0% ("Usual activities") to 3.9% ("Pain/discomfort"). Ceiling effects were reduced in four dimensions. "Usual activities" dimension showed significant reduction (absolute and relative reductions: 3.9% and 4.3%; p = 0.025) and the "worried/sad/unhappy" dimension showed the largest significant reduction in ceiling effects (absolute and relative reductions: 7.8% and 9.8%; p = 0.012). The 3LY and 5LY showed very good agreement (> 80%) of individual dimension responses between two assessments, except for the "worried/sad/unhappy" dimension in 3LY.

CONCLUSION

Through this head-to-head comparison, the 5LY had significant improvements in ceiling effects in two dimensions when compared to 3LY but other measurement properties of 3LY and 5LY performed similar in the idiopathic scoliosis patient group.

The added value of the EQ-5D with a cognition dimension in injury patients with and without traumatic brain injury

Purpose

This study investigated the psychometric gain, if any, from the extension of the EQ-5D with a cognition bolt-on (EQ-5D + C) in a large cohort injury patients with and without traumatic brain injury (TBI).

Methods

Hospitalized adult injury patients filled out a survey 1 month after initial admission. The survey included the EQ-5D-3L, the cognition bolt-on item in EQ-5D format, and the visual analogue scale (EQ-VAS). We compared ceiling and other distributional effects between EQ-5D and EQ-5D + C and TBI and non-TBI group, and assessed convergent validity using the predictive association with EQ-VAS. Also, we assessed explanatory power using regression analysis, and classification efficiency using Shannon indices.

Results

In total, 715 TBI patients and 1978 non-TBI patients filled out the EQ-5D + C and EQ-VAS. Perfect health was reported by 7.9% (N = 214) on the EQ-5D, and 7.3% (N = 197) on the EQ-5D + C. Convergent validity was highest for EQ-5D + C in the TBI group (Spearman’s rank correlation coefficient = − 0.736) and lowest for EQ-5D in the non-TBI group (Spearman’s rank correlation coefficient = − 0.652). For both TBI and non-TBI groups, the explanatory power of EQ-5D + C was slightly higher than of EQ-5D (R² = 0.56 vs. 0.53 for TBI; R² = 0.47 vs. 0.45 for non-TBI). Absolute classification efficiency was higher for EQ-5D + C than for EQ-5D in both TBI groups, whereas relative classification efficiency was similar.

Conclusions

Psychometric performance in general of both the EQ-5D and EQ-5D + C was better in TBI patients. Adding a cognitive bolt-on slightly improved the psychometric performance of the EQ-5D-3L.

Is EQ-5D-5L Better Than EQ-5D-3L? A Head-to-Head Comparison of Descriptive Systems and Value Sets from Seven Countries

OBJECTIVE

This study describes the first empirical head-to-head comparison of EQ-5D-3L (3L) and EQ-5D-5L (5L) value sets for multiple countries.

METHODS

A large multinational dataset, including 3L and 5L data for eight patient groups and a student cohort, was used to compare 3L versus 5L value sets for Canada, China, England/UK (5L/3L, respectively), Japan, The Netherlands, South Korea and Spain. We used distributional analyses and two methods exploring discriminatory power: relative efficiency as assessed by the F statistic, and an area under the curve for the receiver-operating characteristics approach. Differences in outcomes were explored by separating descriptive system effects from valuation effects, and by exploring distributional location effects.

RESULTS

In terms of distributional evenness, efficiency of scale use and the face validity of the resulting distributions, 5L was superior, leading to an increase in sensitivity and precision in health status measurement. When compared with 5L, 3L systematically overestimated health problems and consequently underestimated utilities. This led to bias, i.e. over- or underestimations of discriminatory power.

CONCLUSION

We conclude that 5L provides more precise measurement at individual and group levels, both in terms of descriptive system data and utilities. The increased sensitivity and precision of 5L is likely to be generalisable to longitudinal studies, such as in intervention designs. Hence, we recommend the use of the 5L across applications, including economic evaluation, clinical and public health studies. The evaluative framework proved to be useful in assessing preference-based instruments and might be useful for future work in the development of descriptive systems or health classifications.

Validation and comparison of the psychometric properties of the EQ-5D-3L and EQ-5D-5L instruments in Greece

PURPOSE

To validate and compare the psychometric properties of the EQ-5D-3L with the EQ-5D-5L classification systems in Greece.

METHODS

Participants (n = 2279) over 40 years old, sampled from the greater area of Athens using a multistage stratified quota sampling method, completed both EQ-5D versions, while information was also collected on socio-demographics and health-related characteristics. The EQ-5D-5L and EQ-5D-3L were evaluated in terms of agreement, ceiling effects, redistribution and inconsistency, informativity, and convergent and known-groups validity.

RESULTS

The agreement between the EQ-5D-3L and EQ-5D-5L was high (ICC = 0.85). Ceiling effects decreased significantly in the EQ-5D-5L in all domains (P < 0.001), with "usual activities" (-21.4 %) and "self-care" (-20.1 %) showing the highest absolute and "anxiety/depression" the highest relative reduction (-32.46 %). Inconsistency was low (5.7 %). The increase in prevalence of problems was larger than the decrease in their severity, resulting in a lower mean health utility for the EQ-5D-5L. Overall absolute and relative informativity improved by 70.5 % and 16.4 %, respectively, in the EQ-5D-5L. Both instruments exhibited good convergent and known-groups validity, with evidence of a considerably better convergent performance and discriminatory ability of the EQ-5D-5L.

CONCLUSIONS

Both EQ-5D versions demonstrated good construct validity and had consistent redistribution. The EQ-5D-5L system may be preferable to the EQ-5D-3L, as it exhibited superior performance in terms of lower ceiling effects, higher absolute and relative informativity, and improved convergent and known-groups validity efficiency.

Assessment of Health-Related Quality of Life after TBI: Comparison of a Disease-Specific (QOLIBRI) with a Generic (SF-36) Instrument

Psychosocial, emotional, and physical problems can emerge after traumatic brain injury (TBI), potentially impacting health-related quality of life (HRQoL). Until now, however, neither the discriminatory power of disease-specific (QOLIBRI) and generic (SF-36) HRQoL nor their correlates have been compared in detail. These aspects as well as some psychometric item characteristics were studied in a sample of 795 TBI survivors. The Shannon H (') index absolute informativity, as an indicator of an instrument's power to differentiate between individuals within a specific group or health state, was investigated. Psychometric performance of the two instruments was predominantly good, generally higher, and more homogenous for the QOLIBRI than for the SF-36 subscales. Notably, the SF-36 "Role Physical," "Role Emotional," and "Social Functioning" subscales showed less satisfactory discriminatory power than all other dimensions or the sum scores of both instruments. The absolute informativity of disease-specific as well as generic HRQoL instruments concerning the different groups defined by different correlates differed significantly. When the focus is on how a certain subscale or sum score differentiates between individuals in one specific dimension/health state, the QOLIBRI can be recommended as the preferable instrument.

The EQ-5D-5L is More Discriminative Than the EQ-5D-3L in Patients with Diabetes in Singapore

OBJECTIVES

To compare the discriminative power of the five-level version of the EuroQol five-dimensional questionnaire (EQ-5D-5L [5L]) and its three-level version (EQ-5D-3L [3L]) in patients with diabetes in Singapore.

METHODS

A consecutive sample of patients with type 2 diabetes mellitus (T2DM) self-completed the two versions of the EQ-5D in the clinic. The 3L index score was calculated from the Singapore 3L value set, whereas the 5L index score was mapped from the 5L index score using an interim scoring. The discriminative power of the two EQ-5D indices was assessed in terms of their relative efficiency (RE) in differentiating patients with T2DM with and without one of eight clinical conditions. The efficiency of the two EQ-5D classification systems was evaluated using the Shannon's index (H׳) and in terms of ceiling effects.

RESULTS

A total of 121 patients with T2DM provided data for this study. The 3L score was systematically higher than the 5L score for patients with T2DM with a condition and systematically lower for the patients without a condition, with the mean differences being 0.005 and -0.011, respectively. The 5L index score showed higher RE in seven of eight clinical conditions (mean RE 1.87). The 5L classification system had higher H׳ in all dimensions: mobility (1.17 vs. 0.70), self-care (0.57 vs. 0.41), usual activities (1.01 vs. 0.72), pain/discomfort (1.47 vs. 1.02), and anxiety/depression (1.36 vs. 1.10). The overall ceiling effects decreased from 47.9% (3L) to 38.8% (5L).

CONCLUSIONS

The EQ-5D-5L is more discriminative than the EQ-5D-3L in patients with T2DM in Singapore, supporting the use of EQ-5D-5L in the population.

Should additional domains be added to the EQ-5D health-related quality of life instrument for community-based studies? An analytical descriptive study

Background

There is increasing interest in monitoring the health-related quality of life (HRQoL) of populations as opposed to clinical populations. The EQ-5D identifies five domains as being most able to capture the HRQoL construct. The question arises as to whether these domains are adequate within a community-based population or whether additional domains would add to the explanatory power of the instrument.

Methods

As part of a community-based survey, the responses of 310 informants who reported at least one problem in one domain filled in the EQ-5D three-level version and the WHOQOL-BREF (World Health Organization Quality of Life Scale – Abbreviated version). Using the EQ-5D visual analogue scale (VAS) of rating of health as a dependent variable, the five EQ-5D and four selected WHOQOL-BREF items were entered as dummy variables in multiple regression analysis.

Results

The additional domains increased the explanatory power of the model from 52 % (EQ-5D only) to 57 % (all domains). The coefficients of Self-Care and Usual Activities were not significant in any model. The most parsimonious model included the EQ-5D domains of Mobility, Pain/Discomfort, Anxiety/Depression, Concentration, and Sleep (adjusted r² = .57).

Conclusions

The EQ-5D-3L performed well, but the addition of domains such as Concentration and Sleep increased the explanatory power. The user needs to weigh the advantage of using the EQ-5D, which allows for the calculation of a single summary index, against the use of a set of domains that are likely to be more responsive to differences in HRQoL within community living respondents. The poor predictive power of the Self-Care and Usual Activities domains within this context needs to be further examined.

Measurement properties of the EQ-5D-5L compared to EQ-5D-3L in the Thai diabetes patients

Background

The EQ-5D is a health-related quality of life instrument which provides a simple descriptive health profile and a single index value for health status. The latest version, the EQ-5D-5L, has been translated into more than one hundred languages worldwide - including Thai. This study aims to assess the measurement properties of the Thai version of the EQ-5D-5L (the 5L) compared to the EQ-5D-3L (the 3L).

Methods

A total of 117 diabetes patients treated with insulin completed a questionnaire including the 3L and the 5L. The 3L and 5L were compared in terms of distribution, ceiling, convergent validity, discriminative power, test-retest reliability, feasibility, and patient preference. Convergent validity was tested by assessing the relationship between each dimension of the EQ-5D and SF-36v2 using Spearman’s rank-order correlation. Discriminative power was determined by the Shannon index (H ′) and Shannon’s Evenness index (J ′). The test-retest reliability was assessed by examining the intraclass correlation coefficient (ICC) and Cohen’s weighted kappa coefficient.

Results

No inconsistent response was found. The 5L trended towards a slightly lower ceiling compared with the 3L (33% versus 29%). Regarding redistribution, 69% to 100% of the patients answering level 2 with the 3L version redistributed their responses to level 2 with the 5L version while about 9% to 22% redistributed their responses to level 3 with the 5L version. The Shannon index (H ′) improved with the 5L while the Shannon's Evenness index (J ′) reduced slightly. Convergent validity and test-retest reliability was confirmed for both 3L and 5L.

Conclusions

Evidence supported the convergent validity and test-retest reliability of both the 3L and 5L in diabetes patients. However, the 5L is more promising compared to the 3L in terms of a lower ceiling, more discriminatory power, and higher preference by the respondents. Thus, the 5L should be recommended as a preferred health-related quality of life measure in Thailand.

Electronic supplementary material

The online version of this article (doi:10.1186/s12955-014-0203-3) contains supplementary material, which is available to authorized users.

The EQ-5D-5L index score is more discriminative than the EQ-5D-3L index score in diabetes patients

PURPOSE

To compare the discriminative power of the index scores of EQ-5D-5L (5L) and EQ-5D-3L (3L) in diabetes patients in China.

METHODS

A consecutive sample of type 2 diabetes mellitus (T2DM) patients in the clinics self-completed the two versions of EQ-5D. The 3L index score was obtained from the Chinese 3L value set; the 5L index score was predicted from the 3L index score using an interim scoring. Relative efficiency (RE) of the 5L and 3L index scores was calculated to compare their ability in differentiating between T2DM patients with and without one of ten clinical conditions. The efficiency of the 5L and 3L health state classification systems was assessed using the Shannon index (H') and in terms of ceiling effects.

RESULTS

A total of 289 T2DM patients participated in this study. The 5L score was systematically lower than the 3L score for T2DM patients with and without a condition (range -0.36 to -0.06). The 5L score exhibited higher discriminative power in nine of ten conditions, with the mean RE value being 1.92. 5L had higher H' values than 3L in all the five EQ-5D dimensions: mobility (1.14 vs. 0.70), self-care (0.44 vs. 0.33), usual activities (0.72 vs. 0.47), pain/discomfort (1.58 vs. 1.10), and anxiety/depression (1.03 vs. 0.67). The overall ceiling effects decreased from 56.7 % (3L) to 36.7 % (5L).

CONCLUSION

The 5L index score is more discriminative than the 3L index score in T2DM patients and therefore is preferable for use in this population.

Comparison between the EQ-5D-5L and the EQ-5D-3L in patients with hepatitis B

OBJECTIVES

The purpose of the study was to compare psychometric properties of the EQ-5D-5L (5L) and the EQ-5D-3L (3L) health outcomes assessment instruments in patients with hepatitis B in China.

METHODS

Patients, including hepatitis B virus carriers and those with active or inactive chronic hepatitis B, compensated cirrhosis, decompensated cirrhosis or hepatocellular carcinoma, answered a questionnaire composed of 5L, socio-demographic information, 3L, and the visual analog scale (VAS), respectively. After 1 week, a retest was conducted for inpatients. We compared acceptability, face validity, redistribution properties, convergent validity, known-group validity, discriminatory power, ceiling effect, test-retest reliability, and responsiveness of 5L and 3L.

RESULTS

A total of 369 outpatients and 276 inpatients were recruited for the first interview. Of the inpatients, 183 were used in the retest. Most patients preferred 5L-3L. The 3L-5L response pairs had an inconsistency rate of 2.4%. Correlation with the VAS was greater with 5L than with 3L. Age, education, and comorbidity were associated with health-related quality of life (HRQoL). 5L discriminated more infectious conditions than 3L. In all dimensions, the Shannon's index from 5L was larger while in three dimensions the Shannon's evenness index from 5L was slightly larger. The ceiling effect was reduced in 5L. In patients with stable health states, no significant difference was detected in the weighted kappa between 5L and 3L, but intraclass correlation coefficient of 5L was higher than that of 3L. In patients with improved health states, HRQoL was seen as increased in both 5L and 3L, without significant difference.

CONCLUSIONS

The EQ-5D-5L was more suitable than the EQ-5D-3L in the patients with hepatitis B in China.

Relating health-related Quality of Life to disability progression in multiple sclerosis, using the 5-level EQ-5D

BACKGROUND

Increasing use of the Quality-Adjusted Life-Year to inform resource allocation decision-making has highlighted the importance of relating clinical and health-related quality of life (HRQoL) outcomes in multiple sclerosis (MS) patients.

OBJECTIVE AND METHODS

To investigate the relationship between the Expanded Disability Status Scale (EDSS) and HRQoL utility, using the 5-level EQ-5D (EQ-5D-5L). The discriminatory power of the EQ-5D-5L was assessed using Shannon's indices.

RESULTS

A linear decline in utility was observed with changes in EDSS score from 0 to 6, after which point the relationship exhibited greater variability. Mean utility values ranged from -0.22 at EDSS 9 to 0.88 at EDSS 0. We found that the discriminative capacity of the EQ-5D-5L was considerably lower for the domains self-care and anxiety/depression, compared with other health-related domains.

CONCLUSION

In its first reported use in an MS population, the EQ-5D-5L displayed good discriminatory capacity, although performance differed between the various domains of health, with evidence of a ceiling effect present in the domains of self-care and anxiety/depression. The EQ-5D-5L demonstrated a high correlation with EDSS in our MS cohort up to EDSS 6, after which point the utility valuation of severe health states exhibited much greater variability. Utility estimates from this study may be used in economic evaluations of disease-modifying therapies in MS, to inform resource-allocation decisions.

Comparing the performance of the standard EQ-5D 3L with the new version EQ-5D 5L in patients with chronic hepatic diseases

PURPOSE

To assess the performance of the EQ-5D-5L version compared with the standard EQ-5D-3L in a clinical setting targeted at patients with chronic hepatic diseases (CHDs).

METHODS

We introduced the 5L descriptive system into a cost-of-illness study involving patients with different CHDs. The patients completed a questionnaire including the two versions of the EQ-5D, together with other questions related to their condition. We tested the feasibility, the level of inconsistency, the redistribution properties among consistent responses, the ceiling effect, the discriminative power, and the convergent validity of the 5L compared with the 3L system.

RESULTS

A total of 1,088 valid patients were recruited: 62% male, 19-89 (median = 59) years old. Patients had chronic hepatitis from HCV (31.8%) or HBV infections (29.3%) or other causes (7.8%), 20.4% had cirrhosis, 11.9% underwent liver transplantation, and 7.8% had hepatic carcinoma. Less than 1% of EQ-5D-5L were returned blank, and 1.6% or less of missing values were calculated on the dimensions of the partially completed questionnaires. The proportion and weight of inconsistent responses (i.e., 3L responses that were at least two levels away from the 5L responses) was 2.9% and 1.2 on average, respectively. Regarding redistribution, 57-65% of the patients answering level 2 with the 3L version redistributed their responses to levels 2 or 4 with the 5L version. A relative 7% reduction of the ceiling effect was found. Furthermore, the absolute informativity increased but the relative informativity slightly decreased in every domain, and the convergent validity with the VAS improved.

CONCLUSIONS

In a clinical setting involving CHD patients, the EQ-5D-5L was shown to be feasible and with promising levels of performance. Our findings suggest that the 5L performs better in at least some of the properties analyzed, and encourage further research to also test other psychometric properties of this new version of the EQ-5D.

Measurement properties of the EQ-5D-5L compared to the EQ-5D-3L across eight patient groups: a multi-country study

Purpose

The aim of this study was to assess the measurement properties of the 5-level classification system of the EQ-5D (5L), in comparison with the 3-level EQ-5D (3L).

Methods

Participants (n = 3,919) from six countries, including eight patient groups with chronic conditions (cardiovascular disease, respiratory disease, depression, diabetes, liver disease, personality disorders, arthritis, and stroke) and a student cohort, completed the 3L and 5L and, for most participants, also dimension-specific rating scales. The 3L and 5L were compared in terms of feasibility (missing values), redistribution properties, ceiling, discriminatory power, convergent validity, and known-groups validity.

Results

Missing values were on average 0.8 % for 5L and 1.3 % for 3L. In total, 2.9 % of responses were inconsistent between 5L and 3L. Redistribution from 3L to 5L using EQ dimension-specific rating scales as reference was validated for all 35 3L–5L-level combinations. For 5L, 683 unique health states were observed versus 124 for 3L. The ceiling was reduced from 20.2 % (3L) to 16.0 % (5L). Absolute discriminatory power (Shannon index) improved considerably with 5L (mean 1.87 for 5L versus 1.24 for 3L), and relative discriminatory power (Shannon Evenness index) improved slightly (mean 0.81 for 5L versus 0.78 for 3L). Convergent validity with WHO-5 was demonstrated and improved slightly with 5L. Known-groups validity was confirmed for both 5L and 3L.

Conclusions

The EQ-5D-5L appears to be a valid extension of the 3-level system which improves upon the measurement properties, reducing the ceiling while improving discriminatory power and establishing convergent and known-groups validity.

Preference-based SF-6D scores derived from the SF-36 and SF-12 have different discriminative power in a population health survey

OBJECTIVE

To compare the discriminative power of the SF-6D index scores derived from the SF-36 (SF-6D36) and SF-12 (SF-6D12) in the general population.

METHODS

Data from the National Health Measurement Study were used. The F statistic was used to compare the relative efficiency of the SF-6D36 and SF-6D12, as well as the EQ-5D, HUI2, and HUI3 index scores, in discriminating between respondents with and without 1 of the 11 chronic medical conditions. The efficiency of the multiattribute health classification systems of the study instruments was measured using the Shannon index (H'). The relative efficiency of the SF-6D36 and SF-6D12 was also compared in respondents who were on the ceilings of the EQ-5D, HUI2, and HUI3 scales.

RESULTS

The SF-6D36 score was systematically lower than the SF-6D12 score at the group level (range, 0.022-0.036). The SF-6D36 exhibited higher discriminative power in 8 and 5 conditions than the SF-6D12 and all other index scores, respectively. The SF-6D36 had higher H' values than the SF-6D12 in the dimensions of physical functioning (1.73 vs. 0.78), mental health (1.70 vs. 1.39), and bodily pain (2.16 vs. 1.56) as well as than all other instruments in similar health dimensions. In respondents reporting full health on the EQ-5D, HUI2, or HUI3, the SF-6D36 better discriminated between those with and without medical conditions than the SF-6D12.

CONCLUSIONS

The SF-6D derived from the SF-36 is more discriminative than that derived from the SF-12 and is therefore preferred for use in population health surveys where a preference-based health index is needed.

The effect of comorbidity on health-related quality of life for injury patients in the first year following injury: comparison of three comorbidity adjustment approaches

BACKGROUND

Three approaches exist to deal with the impact of comorbidity in burden of disease studies - the maximum limit approach, the additive approach, and the multiplicative approach. The aim of this study was to compare the three comorbidity approaches in patients with temporary injury consequences as well as comorbid chronic conditions with nontrivial health impacts.

METHODS

Disability weights were assessed using data from the EQ-5D instrument developed by the EuroQol Group and derived from a postal survey among 2,295 injury patients at 2.5 and 9 months after being treated at an emergency department. We compared the observed and predicted EQ-5D disability weights in comorbid cases using data from injury patients with and without comorbidity who were restored from their injuries at 9 months follow-up. The predicted disability weights were calculated using the maximum limit approach, additive approach, and multiplicative approach. The intraclass correlation coefficient (ICC) was used to test whether the values of the observed disability weights and the three model-predicted disability weights were correlated.

RESULTS

The EQ-5D disability weight of injury patients increased significantly with the number of comorbid diseases. The ICCs of the additive, multiplicative, and maximum limit models were 0.817, 0.778, and 0.674, respectively. Although the 95% confidence intervals of the ICCs of the three models overlap, the maximum limit model seems to fit less well than the additive and multiplicative models. For mild to moderate chronic disease (disability weight below 0.21), the association between predicted and observed disability weights was low.

CONCLUSIONS

Comorbidity has a high impact on disability measured with EQ-5D. Ignoring the effect of comorbidity restricts the use of the burden of disease concept in multimorbid populations. Gains from health care or interventions may be easily overestimated if a substantial number of patients suffer from additional conditions. The results of this study found that in accounting for comorbidity effects, all three models showed a strong association between the predicted and observed morbid disability weight, though the maximum limit model seems to fit less well than the additive and multiplicative models. The three models do not fit well in the case of mild to moderate pre-existing disease.

Relative efficiency of the EQ-5D, HUI2, and HUI3 index scores in measuring health burden of chronic medical conditions in a population health survey in the United States

OBJECTIVE

We sought to compare the ability of the EQ-5D, Health Utilities Index Mark 2 (HUI2), and HUI Mark 3 (HUI3) index scores to discriminate between respondents based on the presence or absence of chronic medical conditions in a population health survey.

METHODS

Secondary analyses were conducted with data from a probability sample (n = 3480, mean age: 42.5 years, male: 42.4%, Hispanic: 28.6%) of the 2001 noninstitutionalized US general adult population. F-statistic ratios were used to evaluate the relative efficiency of the EQ-5D, HUI2, and HUI3 in differentiating respondents with or without each of 18 chronic medical conditions, and differentiating respondents with low- or high-burden conditions.

RESULTS

In comparing respondents with and without chronic medical conditions, the F-statistic values of these 3 indices were not significantly different, except for EQ-5D versus HUI2 [mean F-statistic ratio: 0.79, 95% confidence interval (CI): 0.59-0.98]. In comparing respondents with a low-burden condition with those with a high-burden condition, the F-statistic values of EQ-5D and HUI2 index scores were similar, while those for EQ-5D versus HUI3 (mean: 0.79; 95% CI: 0.66-0.92) and for HUI2 versus HUI3 (mean: 0.83; 95% CI: 0.71-0.95) were significantly less than 1.0. The overall ceiling effects of the EQ-5D, HUI2, and HUI3 index scores were 48.9%, 15.4%, and 15.3%, respectively.

CONCLUSIONS

Although the EQ-5D seems to be marginally less informative, the EQ-5D, HUI2, and HUI3 index scores were generally comparable in determining health burden of chronic medical conditions in this population health survey data.

Comparing the standard EQ-5D three-level system with a five-level version

OBJECTIVES

The aim of this study is a head-to-head comparison of the performance of the three-level EQ-5D (3L) and a newly developed five-level version (5L).

METHODS

Eighty-two respondents valued 15 standardized disease descriptions and their own health on three response scales (3L, 5L, and visual analog scale [VAS]) for all five EQ-5D dimensions. Performance was studied in terms of feasibility, face validity, redistribution properties, ordinality, convergent validity, discriminatory power, and test-retest and interobserver reliability.

RESULTS

The majority of participants judged 5L as the preferred system in terms of feasibility (76%) and face validity (75%). In total, 1.1% of responses were inconsistent. Ordinality of 5L was confirmed in all cases. Convergent validity of 3L-VAS (range: 0.88-0.99) and 5L-VAS (0.90-0.99) were high and about equal. Discriminatory power (informativity) improves considerably with 5L without loss of Evenness. Interobserver reliability (0.49 vs. 0.57) and test-retest reliability (0.52 vs. 0.69) were higher in 5L.

CONCLUSION

The EQ-5D five-level version appears a valid and reliable extension of the three-level system. The new 5L system is particularly useful for describing mild health problems and monitoring population health.